Spray paint besmear fits off-gas treatment plan

　　Spray paint besmear holds waste gasComposition analysis:

1. The formation of spray paint waste gas reachs bases

Spray paint often applies at the industry such as mechanical, car, electric equipment, home appliance, shipping, furniture.

Car spray paint origin of organic waste gas- – paint coating by do not volatilize portion and volatilize a composition, do not volatilize the portion includes velar material and material of complementary furtherance film, volatilize portion thinner is to use attenuant paint, achieve the goal with lacquer substance smooth and artistic appearance.

Paint basically produces Qi Wu and pollution of organic waste gas in spray process, paint changes particle in high-pressured action mist, when spray, halfway paint did not arrive at appearance of spray paint substance, form Qi Wu; thereby along with air current dispersion organic waste gas comes from thinner volatilize, organic dissolvent won’t adhere to along with paint in appearance of spray paint substance, will release entirely in spray paint and solidify process form organic waste gas (document report can amount to about a hundred kinds of volatile organic matter, belong to alkyl hydrocarbon, cycloalkanes hydrocarbon, olefin, balmy apperception to add up to) of compound of etc of content, mellow, aldehyde, ketone, ester, aether respectively.

2. Car besmear holds the origin of waste gas and character

Spray paint should undertake lacquer pre-treatment, electrophoresis and spray paint to workpiece. Organic waste gas and sparge mist arose in these processes. Accordingly, these processes need spray booth off-gas treatment.

(Waste gas of 1) spray booth

To maintain the homework environment of spray, according to the delimit of standard of labor safety sanitation, when spray homework, spray booth a person operating from within in coordination with outside forces changes wind continuously, the speed that change wind should be controlled in (inside the limits of 0.25 ～ 1)m/s. Its bases is the organic dissolvent that the main composition that spray booth changes wind exhaust waste gas volatilizes for spray paint balmy hydrocarbon (total hydrocarbon of 3 benzene and blame firedamp kind) , mellow aether kind, ester kind organic dissolvent because the platoon wind force of spray booth is very large so the organic waste gas of eduction total. In addition, often contain in the exhaust of spray booth a few paint mist, do lacquer fog chamber especially, more paint mist is contained in its waste gas, the likelihood becomes the obstacle of off-gas treatment, pretreatment must undertake before off-gas treatment.

(Waste gas of room of 2) air buy

Face lacquer is in after spray before stoving, want to undertake drifting making the same score air buy, wet paint film volatilizes in air buy process, produce an accident to prevent market of cohesion of air buy room, air buy room should change wind continuously, change wind speed to spend ordinary control to be controlled in 0.2m/s, the part close of the composition of the waste gas that discharge wind and waste gas of wind of spray booth platoon, but do not contain Qi Wu, the total chroma of organic waste gas slants than spray booth waste gas big, UV light solves equipment to produce manufacturer, differ according to discharging wind force size, be in commonly pH indicator of spray booth waste gas 2 times the left and right sides, can achieve 300mg/m3, the concentration after discharging wind to mix with spray booth normally is handled. Additional, move cistern of loop of lacquer of Qi Jian, face to also discharge similar organic waste gas.

(3) drying waste gas

The part of stoving waste gas is more complex, contain plasticizer of machine dissolvent, branch or colophony monomer to wait except the bag volatilize composition, still include live thing of day of pyrolysis day live thing, reaction. Electrophoresis priming paint and solvent face lacquer can discharge waste gas in dry process, dan Jicheng is divided and chroma differs very big.

The harm of spray paint waste gas:

The analysis is knowable, come from room of buy of spray booth, air, attune the waste gas between sewage disposal is lacquer of the knead dough between lacquer the normal temperature waste gas of low density, large flow, the main composition of contaminant is balmy hydrocarbon, mellow aether kind with ester kind organic dissolvent. Contrast ” air pollution discharges a standard integratedly ” , the chroma of these waste gas is being discharged commonly be restricted to be worth less than, line of equipment of sports equipment dusting, ask to rate is being discharged in the standard to answer, most car plant adopts the measure that headroom discharges. Although this kind of method can be satisfied,discharge a standard currently, but waste gas basically is without processing and dilute. The air contaminant gross that general besmear wiring discharges may be as high as hundreds tons every year, destroy to atmospheric very serious.

The organic dissolvent in Qi Wu, benzene, toluene, xylene belongs to strong noxiousness dissolvent, send out when exercise to workshop air in, after worker classics respiratory tract is inspiratory, can cause acute and chronic and toxic, basically cause the harm of central nervous system and hemopoietic system, short-term and inspiratory Gao Nong is spent (the benzene steam of 1 500 M}/ms) , can cause aplastic anemia; often inspiratory low pH indicator benzene steam, also can cause the neurosis condition such as faintness of leaf of disgusting, vomit, god wisdom, minority still can cause neurasthenia Hou Qun.

Spray paint besmear holds option of off-gas treatment method:

Choose organic processing technique, limited company of equipment of grand rich environmental protection can consider the following factor on the whole: The type of organic contaminant and its chroma, organic exhaust temperature and the contaminant that discharge content of content of discharge, grain and need to achieve control a standard.

1, the processing of spray paint normal temperature

Come from room of buy of spray booth, air, attune the normal temperature waste gas that the waste gas of Qi Xinfeng of the knead dough between lacquer is low density, large flow, the main composition of contaminant is balmy hydrocarbon, mellow aether kind with ester kind organic dissolvent. Contrast GB16297 ” air pollution discharges a standard integratedly ” , the chroma of these waste gas is being discharged commonly be restricted to be worth less than, ask to answer a standard to discharge rate mediumly, eletroplate waste gas administers a principle, most car plant adopts the measure that headroom discharges. Although this kind of method can be satisfied,discharge a standard at present, but of waste gas discharging is dilute is discharged substantially, large automobile body besmears outfit line can discharge the aeriform contaminant that is as high as hundreds tons every year, cause serious harm to atmosphere.

The processing of waste gas of spray paint normal temperature is from go up at all those who reduce waste gas contaminant discharge, eletroplate waste gas, can use method of a few kinds of off-gas treatment to undertake handling jointly, but the off-gas treatment cost of large wind force is very high. Current, abroad’s relatively mature method is, condense organic waste gas first with adsorption – desorption runner condenses gross 15 times the left and right sides, need the gross of organic waste gas of processing in order to decrease, use ruinous method to undertake handling to concentrated waste gas again. Home also has similar method, use carbon of adsorptive law active or zeolite to make sorbent undertake adsorption to waste gas of spray paint of low density, normal temperature first, manufacturer of off-gas treatment equipment, with desorption of high temperature gas, concentrated waste gas uses catalytic combustion or method of flaming of heating power of type of accumulation of heat undertakes handling. The biology processing technique of waste gas of spray paint of low density, normal temperature is in research and development, the skill that home shows level is still immature, eletroplate waste gas administers a technology, but be worth to pay close attention to. The pollution that installs to reduce besmear truly is endangered, still need to solve a problem from fountainhead, if use electrostatic the utilization rate that unplugs the method such as coal tub raises coating, develop environmental protection coating, be like coating of ability in swimming.

2, stoving off-gas treatment

Dry waste gas belongs to waste gas of high temperature of medium, high concentration, agree with use combustion law processing. Does combustion reaction have an important parameter: ? Dew of ⑽ going straight towards Huan takes ⑷ oh condition of Zha of  cloth Ci Ji. The efficiency of off-gas treatment basically is enough combustion response rate, this depends on the 3T condition control that combustion reacts. RTO can control combustion temperature (900 ℃ of 820 ～ ) and linger time (1 ～ 1.2s) , assure to disturb necessarily (air and spray content mix) adequately, the processing efficiency of spray waste gas can be amounted to 99% , and useless heat reclaims lead tall, moving specific power consumption is inferior. Plant of day endowment car uses the majority of Japan and home normally RTO is right stoving (, in drying of lacquer of besmear, face) waste gas undertakes centralized handling. But because equipment of RTO catalytic combustion is one-time investment is higher, when be being used at the off-gas treatment with waste gas lesser discharge wasteful.

Hold product line to the besmear that already built, when needing to add off-gas treatment equipment, can use catalytic waste gas to burn system and system of combustion of heating power of type of accumulation of heat. Investment of catalytic combustion system is small, combustion specific power consumption is low.

Generally speaking, use palladium / platinum serves as activator but oxidation great majority the oxidation thermal drop of organic waste gas is controlled to 315 ℃ . Catalytic combustion system can be used at the processing of general and dry waste gas, special the report that applies to dry power source heats. The problem that exists at present is how to avoid activator toxic invalidation. From the point of the use experience of a few users, to waste gas of general face lacquer drying, eletroplate waste gas, wait for measure through increasing waste gas to filter, eletroplate off-gas treatment means, the life that can assure activator is 3 ～ 5 years waste gas of drying of; electrophoresis lacquer causes activator easily toxic, so the processing of waste gas of electrophoresis lacquer drying should use catalytic combustion means cautiously. The off-gas treatment that holds a line in besmear of commercial vehicle automobile body transforms a process in, eletroplate waste gas, waste gas of drying of electrophoresis priming paint uses waste gas of drying of lacquer of Rto law processing, face to use processing of catalytic combustion pattern, use result is favorable.

Spray paint besmear installs off-gas treatment technology:

Plan of spray industry off-gas treatment basically is used at spray, furniture factory, machinery is made, the factory that protect column, car is made, the off-gas treatment between 4S workshop spray. Put in the processing technology of a variety of organic waste gas at present, be like: Condensation law, absorb law, combustion law, catalysis law, adsorptive law, biology law and plasma law to wait.

1, water gush drenchs law + desorption of activated carbon adsorption + catalytic combustion

Use gush to drench mist of tower eliminate lacquer is mixed but dissolve the material at water, repass does type filter, go in device of activated carbon adsorption, wait for activated carbon when adsorption is full, again desorption (desorption method has vapour desorption, report to heat) of desorption, nitrogen desorption, the gas after desorption (chroma is more original rise a few times) enter combustion of catalytic combustion device by desorption fan, combustion becomes carbon dioxide and water, back row goes out.

2, water gush drenchs + desorption of activated carbon adsorption + condensation absorption method

Equipment of Zhenjiang spray off-gas treatment: Use gush to drench mist of tower eliminate lacquer is mixed but dissolve the material at water, repass does type filter, go in device of activated carbon adsorption, wait for activated carbon when adsorption is full, again desorption, the condensation after the waste gas adsorption after processing condenses, condensate reclaims via depart valuable organic matter. This law spends tall, temperature with Yu Nong off-gas treatment of hidebound of low, wind. But this law invests big, specific power consumption in waste gas of big spray paint of tall, moving charge ” 3 benzene ” reach consistency of other waste gas commonly under Mgm chroma small wind force is large (the wind force of workshop of spray paint of automobile manufacturing industry often is in above of 10 thousand class) and in because the car besmears,holding waste gas organic dissolvent.

3, law of waste gas adsorption

But cent is absorbed for chemistry and physics is absorbed, but active of chemistry of 3 benzene waste gas is low, do not use chemistry to absorb commonly. Physics absorbs fluid less volatile, the part that it draws has taller affinity heat, equipment of waste gas of catalysis of industrial smooth oxygen, refrigeration and recycle analysis saturation are absorbed. This method is used at capacity, microtherm is spent, low density. Installation is complex, investment is large, the choice that absorbs fluid is more difficult, have two pollution.

4, active carbon is adsorptive + facilities of combustion of UV smooth catalysis

6, adsorptive law: (1): ? Plutonium of  of benzene oily ü accumulate fear benzene swimming  receives? of  thanking  to achieve purifying rate 95% , equipment is simple, investment is small, the operation is convenient, but need often changes active carbon, low density contaminant, without restore. (: of 2) adsorptive law? Plutonium of joke of Wei of  thanking  accumulate desorption of air of saturation of activated carbon of class  ? and second birth.

5, activated carbon is adsorptive + microtherm plasma equipment

2, ionic oxygen purifies systematic ion law is to use plasma Plasma(ION plasma) degradation organic waste gas, dispel is effluvial, exterminate bacterium, virus, purifying air is the more sophisticated new and high technology on international, domestic and international expert says for science of 21 centuries environment one of 4 old techniques. The key of this technology is the formal generation that holds back discharge through high-pressured pulse medium a large number of active and ionic oxygen (plasma) , activation gas, produce all sorts of active freedom base, o of HO2 of the OH that be like · , · , · , hydrocarbon of angry to benzene, toluene, xylene, ammonia, alkyl kind wait for organic waste gas to produce the complex physics such as degradation, oxidation and chemical reaction, and by-product is avirulent, avoid 2 times to pollute. This technology has specific power consumption extremely low, cover an area of a space small, move safeguard wait for a characteristic simply, apply to a variety of constituent especially the processing of organic gas.